Clearing Haze from your beer
Clear Your Beer: Cut through the haze and fine your way to maximum clarity Historically speaking, clear beer is a recent invention. For most of its history, beer was a dark, cloudy beverage. In British pubs in the 1100s, patrons would pass around an earthenware bowl with lines marked on the inside. Each patron would take it down a peg for a penny and pass the bowl on. In those dark, smoky pubs the appearance of beer was basically irrelevant.
Attitudes towards the appearance of beer began to change with the widespread use of clear glass. Once beer drinkers could see their beer, they began favoring clearer beer. Today, bar patrons want crystal clear beer for their pennies.
For the homebrewer, clearing is both an aesthetic concern and a stability issue. Clear beer not only looks better, but it is more stable than cloudy beer. A beer with elevated levels of haze will have the tendency to deteriorate rapidly.
Types of Haze
There are different kinds of haze that form in beer. These include permanent haze, yeast haze and chill haze. Permanent haze is, as the name suggests, a haze that does not go away. The presence of permanent haze is evidence of a serious problem in the brewing process. Once formed, it cannot be eliminated without further damaging your beer. Permanent haze can be due to biological contamination or an excess of starch in your wort. If the haze is biological, you need to pay closer attention to your cleaning and sanitizing procedures. If you have starch haze, you need to ensure you are getting complete conversion in your mash. Do not run your wort off until the iodine test gives a negative result. If you use good ingredients and your brewing procedures are fundamentally sound, it is not very likely that you will encounter this type of haze. Yeast haze affects all beers unless something is done to counteract it. After fermentation, yeast can remain in suspension indefinitely. If you use flocculant yeast and store your beer cold, the amount of yeast haze in your beer will probably be minimal. However, if you want a beer that sparkles you will need to get rid of it.
Chill haze is a haze that forms when beer is cooled and disappears when the beer warms up. Repeated heating and cooling cycles can cause chill haze to turn permanent. Chill haze is formed when proteins in the beer bond weakly with polyphenols (also called tannins). The level of chill haze in beer increases over time. There are three ways to minimize or reduce chill haze: reduce the amount of haze-forming proteins, reduce the amount of polyphenols and remove the protein-polyphenol complexes after they have formed.
Assessing Haze in Your Beer
To see how hazy your beer is with your current brewing procedures, try this test. Take two of your homebrews and one commercially brewed beer of the same style. Leave the beers at room temperature until the day before the test. The night before, put one bottle of homebrew in the fridge. Leave the other out at room temperature. You can chill the commercial beer or not, it does not matter.
Take three identical glasses and pour out the three beers. Be careful not to pour out any of the yeast sediment from the homebrews. Compare the commercial beer to the room temperature beer by holding both up to a window or light. Any difference in clarity will be due to yeast haze. The commercial beer should not have yeast haze and chill haze will not have formed in the room-temperature homebrew. Unfiltered homebrew will probably be clear, but it will have a slight dullness when compared to the commercial beer.
To assess the amount of chill haze in your beer, you will need to compare the room temperature homebrew to the chilled one. Any additional haziness in the cold beer will be due to chill haze. As you will see, it is chill haze that usually contributes more to the overall haze of your beer. Finally, compare your cold homebrew to the commercial beer. After seeing your beer next to a crystal clear beer, do you want yours to look better? If you do, then you will have to keep reading to get the lowdown on fining techniques.
Techniques for Clearing Your Beer
A well-made and properly-stored beer will naturally be somewhat clear. The techniques listed in this column can help polish such a beer to make it much clearer. They are not designed to rescue poorly made beers. Removing yeast haze from beer at the peak of fermentation, the concentration of yeast is about 50 million cells per milliliter. Most of the clearing happens without any interference from the brewer. Allowing the yeast to completely settle in secondary goes a long way towards eliminating yeast haze. Proper beer storage also helps minimize yeast haze. Ideally, beer should be stored at 40F after it has bottle conditioned at room temperature. Once it is ready, you should move it to a fridge or somewhere cold, and keep it there until you drink it.
Fining with Isinglass
Beer can be fined with isinglass to remove yeast cells. Isinglass is an extract from the swim bladders of sturgeon. Isinglass is rich in collagen, which binds to yeast cells in solution. The collagen-coated yeast drop out of solution. Isinglass usually comes in powder form. New developments in isinglass powders allow for a simpler process. You can buy treated isinglass powders that simply dissolve in water. If you cannot find the powder, here is the traditional way. It works well at clearing yeast, but it does take some preparation time to use properly.
The isinglass solution must be made in advance and the pH must be adjusted. Finally, it needs to be stored cold to equilibrate. You should wait until the beer has settled as much as possible before adding isinglass. To fine your beer with isinglass, use the following procedure:
Step 1. Dissolve 30 to 60 mgL in a volume of water equal to 1 percent of your batch size. For a 5-gallon batch, add 0.5 to 1.0 grams of isinglass to 200 mL of water. Use distilled water. For best results, gradually add water to the powder.
Step 2. Lower the pH to 2.5 to 3.0 with phosphoric acid. Add the phosphoric acid gradually and check the pH as you go. Be sure to stir thoroughly after each addition and wait a minute after stirring before you take a pH reading.
Step 3. Store the isinglass solution in the refrigerator for two to three days before use.
Step 4. Add to your beer. If you use a bucket, you may want to stir quietly with a sterilized spoon. If you ferment in a carboy, give it a little swirl to distribute the isinglass. In either case, try not to disturb the wort too much.
Step 5. Allow the isinglass to settle overnight.
Step 6. Bottle or keg your beer.
Removing haze-causing proteins from beer
Limiting the amount of haze causing protein in your beer starts before you start brewing before you even buy your ingredients, actually. Brewing strains of barley have been selected to be low in protein compared to feed strains. The choice of brewing ingredients can also affect beer clarity. Beers made with dark malts are usually clearer than paler beers. Throughout the brewing process, there are opportunities to remove protein from your beer. For all-grain brewers, certain malts may require a protein rest. (Most modern malts are well-modified and do not require a protein rest.) When the wort is boiled, a hot break is formed. This break material, which is partially composed of proteins, should be left behind in the kettle when the beer is moved to the fermenter. Likewise, the cold break is left behind when a homebrewer moves his beer to the secondary. And finally, proper storage reduces the amount of chill haze in beer.
If stored cold, chill haze will form and settle out of your bottles in about a week. You can prove this to yourself by comparing a beer that has been in the refrigerator for a week with a beer that has been stored at room temperature and cooled overnight. (Whenever my wife complains that all the space in the fridge is taken up by beer, I immediately launch into a lecture on protein/polyphenol precipitation. It never helps, but I sure get a kick out of saying protein/polyphenol precipitation.
SEE ADDITIONAL READING ON CLEARING YOUR BEER OR WINE